甜瓜种质资源遗传多样性的SRAP分析

Genetic diversity of a germplasm collection of Cucumis melo L. using SRAP markers

为研究甜瓜材料之间的亲缘关系及其分类,更有效地利用种质资源,为培育新品种提供依据,文章采用SRAP(Sequence-related amplified polymorphism)技术对61份甜瓜种质资源的遗传多样性进行研究。结果表明:从42对引物组合中筛选出16对扩增条带清晰、多态性高的引物组合分析供试材料,共检测出452个位点,其中265个为多态性位点,多态性比率达58.63%,平均每对引物组合产生28.56个位点和16.56个多态性位点。61份材料间的相似系数为0.48～0.93,平均为0.73。这些结果说明,供试甜瓜材料具有较为丰富的遗传多样性。聚类分析结果表明,61个甜瓜品种中首先可分为薄皮甜瓜与厚皮甜瓜两大类,彼此亲缘关系最远。以遗传相似系数0.74为截值,可把供试材料分为5个类群。在生态区域中,新疆厚皮甜瓜的Nei’s基因多样性指数(0.2231)和Shannon’s信息指数(0.3422)最高。

Genetic relationships and classifications of a set of melon accessions were analyzed to provide the experimental support for utilizing effectively genetic materials for breeding. Sequence-related amplified polymorphism technique was adopted to analyze 61 melon accessions. Sixteen primer combinations with clear band pattern and polymorphism were selected from over 42 primer combinations. Four hundred and fifty-two loci were detected by 16 pairs of SRAP primers.Among them,265 were polymorphic,the polymorphic rate was 58.63%,and 28.56 loci and 16.56 polymorphic loci were amplified by each pairs of primers on average. The genetic similarity coefficient of the 61 accessions ranged from 0.48 to 0.93,with an average of 0.73. These results suggested that there was rich genetic diversity among the melon accessions tested. The varieties examined were clustered into two groups,which were thick-skinned melon and thin-skinned melon.Five groups were clustered according to genetic similarity coefficient of 0.74. The Nei＇s gene diversity index and Shannon＇s Information index of melon were 0.2231 and 0.3422,respectively,in Xinjiang,the highest among all the ecological regions.